text: 'use strict';
  
  module.exports = function fizzBuzzTree(tree) {
  
    let _walk = (node) => {
      if (node.left) {_walk(node.left);}
  
      if(node.value % 15 === 0) {node.value = 'FizzBuzz';}
      else if (node.value % 3 === 0) {node.value = 'Fizz';}
      else if (node.value % 5 === 0) {node.value = 'Buzz';}
  
      if (node.right) {_walk(node.right);}
    };
  
    _walk(tree.root);
    
    return tree;
    
  };
  